Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

KP322 > FAT ENERGY > Flashcards

FAT ENERGY Flashcards

1
Q

sources of fat during exercise

A

intramscular triglycerides: primary source in high intensity
- trained individuals use muscle more effectively

plasma FFA: from adipose tissue lipolysis
- triglycerides –> FFA + glycerol
- low intensity
- important as musc glycogen lvls decline
- subcutaneous fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

lipolysis

A

breaking down of triglycerides via lipase enzymes

TGs are only useful fat for energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how many carbons in FFAs

A

varies

this is why ATP produced via beta oxidation varies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

main triglyceride sources

A
  1. adipocytes: fat storage across body via adipose tissue cells
  2. intramuscular TG
  3. blood lipoproteins: form of cholesterol i.e. HDL, LDL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

6 stages of lipid breakdown

A
  1. mobilization
  2. transport
  3. uptake
  4. activation
  5. beta-oxidation
  6. mitochondrial oxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mobilization

A

triglyceride breakdown

hormone sensitive lipase: aka HSL
- ATP input needed for adipose and muscle activation

lipoprotein lipase: LPL

***ATP cleaves FFA off, which are then transported to muscle for energy
- 1 ATP/FFA
- remaining glycerol goes to liver to become glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

transport

A

FFA circulates in blood by binding to ALBUMIN carrier protein
- bcs hydrophobic

in cells, FAs are activated via carnitine transferase…then transported across cell membrane into mitochondria for oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

uptake

A

active transport into muscle cytosol

special transport proteins used to move FFA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

activation

A

prepare for breakdown

coa is added to FFA…becomes fatty acyl-coa
- this requires ATP

then moves across membrane into mitochondria via carrier

during b-oxidation, acyl coa is cleaved off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

beta-oxidation

A

FFA is broken down in mitochondria

acyl coa dehydrogenase makes FAD –> FADH2

b-hydroxyacyl coa dehydrogenase makes NAD –> NADH

produces fatty acl coa, which is recycled to continue b-oxidation

also makes acetyl coa, which goes to krebs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

mitochondrial oxidation

A

b-oxi products go to TCA and ETC

FADH2 and NADH go to ETC
acetyl coa goes to krebs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

rule for b-oxi cycles and FAs

A

c/2 - 1 = number of cycles i.e. 7

of carbons is important i.e. 16c

of acetyl coa = #c/2 i.e. 8

b-oxi cannot occur with 2 carbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

products of b-oxi

A

each cycle makes:

1 NADH
1 FADH2
1 acetyl coa (3 NADH, 1 FADH, 1 ATP)

total 14 ATP
net = 12 ATP (2 invested to acquire FA)

2 invested PER fatty acid
- i.e. for 3 FAs, subtract 6 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does glycerol do after it’s cleaved from TG

A

can be used as energy source
- converted to form the liver can use for glycolysis
- does NOT contribute during exercise

1 ATP used to phosphorylate glycerol to G3P
- also reduces NAD –> NADH
- proceeds to glycolysis, making pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

glycerol metabolism

A

glycerol –> G3P

2 ATP + 2 NADH + acetyl coa (3 nadh, 1 fadh, 1 atp)

1 glycerol = 17 ATP
net = 16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what about protein

A

contributes very little
has nitrogen, even more steps to become energy

not often used

17
Q

carb vs fat

A

carb: limited stores
fat: almost unlimited

carb 20% more efficient, allows exercise at high intensity
- faster rate, less o2 use

18
Q

when do energy systems contribute

A

phosphagen 10 seconds
anaerobic 1-2mins
equal by 75s
aerobic dominates after 2 minutes

19
Q

which system dominates at rest

A

aerobic, almost 100% ATP

20
Q

MET

A

metabolic equivalent of a task

1 MET = 3.5ml/kg/min
- resting o2 consumption

is relative to person’s musc mass

21
Q

vo2

A

volume of o2 consumed/minute

L/min is absolute value

ml/kg/min when divide by body weight…allows to compare size/BW effectively

the larger the person, the higher the absolute vo2

22
Q

rest-to-exercise transition

A

ATP production immediately increases

o2 uptake rapid inc, but NOT instantaneous

steady state w/in 1-4 mins after ATP requirement is met thru aerobic metabolism

23
Q

o2 deficit vs o2 debt

A

o2 deficit: lag in o2 uptake at beginning of exercise

o2 debt: repayment for o2 deficit at onset of exercise
- original term for EPOC

24
Q

recovery from exercise

A

o2 uptake remains elevated above rest

EPOC: excess post-exercise oxygen consumption
- repayment for o2 deficit
- separated by rapid and slow phase

25
Q

rapid vs slow phase EPOC

A

rapid phase: steep decline in vo2 (consumption) post-exercise
- 2-3mins
- o2 needed to resynthesize ATP and PCr, and replace tissue stores of o2
- 20% EPOC

slow phase: 30 minutes post exercise, slow dec in o2 consumption

why o2 is still elevated after exercise:
1. gluconeogenesis from lactate
2. HR and breathing elevated
3. elevated blood temp
4. elevated hormone concentration
5. others: glycogen depletion, ph restoration, uncoupling ATP

26
Q

comparing trained vs untrained EPOC and lactate

A

trained: lower o2 deficit, better developed aerobic capacity
- bcs of CV and musc adaptations
- less lactate and H production
- faster o2 uptake via offloading to muscles

27
Q

fate of lactate

A

used as fuel for heart and brain
- becomes acetyl-coa

oxidized in other tissues 60%

forms glucose in liver and stores as glycogen 25%

forms proteins 15%

excreted

28
Q

lactate shuttle

A

lactate is produced in one tissue and moves to another

bcs lactate is an important cell signal/fuel
- originally thought as waste

29
Q

how does lactate become glucose

A

by the cori cycle in the liver

30
Q

cori cycle

A

lactate produced by muscle and is transported to liver
- a lactate shuttle

in liver, lactate becomes glucose via gluconeogenesis

glucose transports to muscle, where it’s used in glycolysis

31
Q

lactate threshold

A

point where blood lactate concentration rises systematically during incremental exercise
- aka pt where lactate accumulates
- also called anaerobic threshold

when blood lactate lvls are 1mmol/L GREATER than resting values

no longer able to handle lactate production rate
- if continue, become fatigued

trained ppl reach threshold later, closer to VO2 max

32
Q

OBLA

A

onset of blood lactate accumulation

when blood lactate lvls reach 4mmol/L
- not above rest
- begins to accumulate at more accelerated rate

train to perform at this lvl for as long as possible

33
Q

what causes ppl to reach lactate threshold faster

A

low musc o2
accelerated glycolysis, produces more lactate
recruitment of fast twitch fibres: fatiguable
reduced lactate removal
LDH isozyme: catalyzes lactic acid + LDH –> lactate

34
Q

why do we measure lactate threshold

A
  1. training status
  2. predicts endurance performance
  3. establishes training intensity…program to inc threshold
35
Q

specificity of OBLA

A

characterized by exercise task specificity

diff exercise modes CANNOT have interchangeable OBLA

i.e. cannot compare running to cycling

36
Q

crossover concept

A

shift from fat to carb as intensity increases

due to recruitment of fast twitch fibres and inc blood levels of epinephrine

KP322 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions